1. Field of the Invention
The present invention relates to a method of manufacturing a flexible impact-resistant material, particularly but not exclusively flexible protective material for use in protective wear and footwear, and to the flexible impact-resistant material produced by this method.
2. Description of Related Art
Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
Protective, impact-resistant materials are currently used to produce clothing and protective articles to protect the person from knocks, abrasions and other injuries whilst playing sports and games, in particular in person to person contact sports such as American football and rugby and in equestrian sports. Occupations such as the building trade also use protective clothing to protect the person where there is a relatively high risk of injury.
Conventional protective wear may form an integral part of an item of clothing, for example a shoulder pad, or be provided separately, for example a shin pad. Protective insoles and shoe uppers may also be produced using flexible material. The flexible material produced by the method disclosed herein is suitable for use in all of these applications as well as for use in upholstery, luggage and in medical applications such as protective coverings for various parts of the body.
Some conventional protective materials take the form of a moulded foam article shaped to fit a particular part of the body. Such mouldings, however, have the disadvantage that they have to be produced in different sizes to fit different people. Provision of different sizes can be expensive or inconvenient. Also, closely fitting articles can restrict movement of the wearer, especially when worn on or near joints. A moulded foam article can only correctly fit a joint when in one position. When the joint moves, the article will no longer fit correctly. This may reduce the protection it affords.
Another existing material comprises a quilted material including lengths of foam sewn into pockets formed between two layers of fabric. Such materials are time consuming to produce. Also, such materials can generally only easily be flexed in a direction perpendicular to that of the strips of foam. Flexing the material in a direction along the length of the strips involves flexing the strips themselves which, depending on the type of foam used, can be difficult.
In WO 01/03530 is described a flexible material comprising a layer of closely spaced yet separate resilient elements joined to a flexible, resiliently stretchable substrate. Such a material overcomes the disadvantages of the materials described above and provides a flexible material that can confirm more easily to the body of the wearer than conventional materials as it is flexible in all three dimensions. It is therefore more comfortable to wear and can accommodate movement better than conventional materials. When used as a protective material or to form protective wear a single size, or a reduced number of sizes, can fit many differently sized bodies.
The method of manufacturing the material described in WO 01/03530 comprises the steps of                providing a sheet of a resilient material;        cutting the sheet into a plurality of spaced, separate elements using a cutter which is pressed into the sheet to cut therethrough;        making one side of the spaced elements to stand proud of the surface of a jig provided to hold the elements in place; and        bonding a flexible, resiliently stretchable substrate to one side of the separate elements by heating the substrate either to active an adhesive applied between said one side of the separate elements and the substrate or to weld the elements to the substrate.        
The elements preferably take the form of blocks and whilst they can be of irregular shape, in most applications they are regular and typically, square, hexagonal or octagonal in cross-section. Again, whilst in some applications only a few large elements are required, in most applications there is a large number of elements that are evenly distributed on the substrate with a density of between 100 and 8000 elements/m2, and most preferably with a density between 4000 and 6000/m2. For this reason, it is necessary to provide a jig that holds the elements in place while the substrate is bonded to them. Advantageously, the cutter is used to act as the jig and may be specially adapted by the provision of blocks or ejectors to make one side of the elements stand proud of the cutting edges of the cutter after cutting to enable this side of the elements to be bonded to the substrate.